There have been conventionally known a substrate holding apparatus for holding substrates such as silicon wafers, compound semiconductor wafers and the like. One example of the substrate holding apparatus may include a Bernoulli chuck which uses Bernoulli's principle to adsorb and hold a substrate in a non-contact state.
However, the above substrate holding apparatus had difficulty in holding a bent substrate. The reason is that, in case of the bent substrate, only gas is likely to be drawn into a space between a bottom surface of the bent substrate and a top surface of the holding apparatus.